1. Field to which the invention relates
The present invention relates to a double sector cell for an ultra-centrifuge comprising a tubular housing which comprises, in the following order as stated, a lower window holder, in which a lower window is located, a cell arrangement and an upper window holder, in which an upper window is located, and has radial filling openings, which allow access to one respective cell of the cell arrangement and are adapted to be closed by respective sealing plugs.
The present invention is particularly useful in an analytical centrifuge of the type described in U.S. Pat. No. 3,518,012 wherein reagents are placed within a centrifuge cell and optically analyzed while undergoing centrifugal forces. The cell of the present invention is adapted for direct replacement of conventional analytical cells used in centrifugal devices of this type.
2. The prior art
The periodical "Biophysical Chemistry" 3 (1975), pages 153 to 160, describes a method for determining equilibrium constants from measurements of the sedimentation diffusion equilibrium data using an ultra-centrifuge, in the case of which a reacting mixture is compared with a non-reacting mixture of the same composition on the basis of its optical absorption or of interferrometry. For carrying out such investigations the conventional center piece of the centrifuge double sector cell is replaced by two contacting center pieces.
In accordance with the analytical technique described in the referenced article, tandem double-sector specimen cell chambers are arranged so that light used for specimen analysis is caused to simultaneously pass through upper and lower specimen chambers. Thus, in order to carry out the analytical technique of the article it is necessary to use an analytical cell for the ultra centrifuge which includes upper and lower specimen cell pairs, so that light may be passed through the upper and lower cells simultaneously and may be sequentially passed through adjacent pairs of upper and lower cells. Thus, the analytical technique requires the use of tandem double-sector analytical cells.